1. Field of the Invention
The present invention relates to a heat exchanger and a method of making the heat exchanger, and is effectively applied to a heat exchanger disposed in a vehicle.
2. Description of Related Art
Conventionally, a header tank of a heat exchanger such as a radiator includes a metallic core plate and a resin tank body, which are integrated with each other. Tubes are joined to the metallic core plate, and the tank body defines a tank space. The core plate and the tank body hold a packing (sealing member) made of an elastic material, such as rubber, therebetween. The packing seals between the core plate and the tank body by compressing the packing between the core plate and the tank body. However, it is difficult to automate a process of attaching the packing to the tank body or the core plate, because the packing is soft and large in size.
For the measures against this, an attaching method is proposed (see, e.g., WO2008/030015) for automating the process of attaching the packing to the tank body. In the method, the tank body is inserted into a molding die, and then the tank body and the packing are integrally formed with each other. By the method, the packing can be formed integrally with the tank body with a high degree of dimension accuracy.
However, by the method described in WO2008/030015, there is a problem of burr generation. Specifically, a rubber material for molding the packing may leak from an interspace between the tank body and the molding die, because the rubber material is injected into a cavity of the molding die with high pressure. Thus, the leakage of the rubber material causes the burr generation.
In order to prevent the burr generation, a size of the interspace between the tank body and the molding die needs to be limited to a few micrometers. To this end, the die clamping force on the tank body and the molding die needs to be high. However, if the mold die clamping force is high, the tank body, which is made of resin, may deform.